OP-TEE Implementation Analysis Required for i.MX93 Systems

[ajlennon]

Issue Description

The current OP-TEE signature verification test (boot_005) may not be providing complete validation of secure world implementation on i.MX93 systems. While the test currently passes by recognizing EdgeLock Enclave (ELE) as an alternative to OP-TEE, we need to ensure this is the correct architectural assumption.

Current Behavior

The test currently:

1. ✅ PASSES by detecting ELE as an alternative to OP-TEE
2. Reports: "i.MX93 EdgeLock Enclave provides secure world functionality (alternative to OP-TEE)"
3. Assumes ELE replaces OP-TEE functionality completely

Concerns

1. Incomplete Analysis: We may be making assumptions about ELE replacing OP-TEE without full verification
2. TEE Infrastructure Present: The test detects TEE device nodes (/dev/tee*) but OP-TEE not fully initialized
3. Mixed Architecture: i.MX93 might support both ELE and OP-TEE in different configurations
4. Security Gap: If OP-TEE should be present and isn't, we're not flagging a potential security issue

Investigation Required

1. Architecture Verification

• Confirm if i.MX93 systems should have OP-TEE in addition to ELE
• Verify if ELE completely replaces OP-TEE functionality or complements it
• Check Foundries.io LMP documentation for intended secure world architecture

2. Current System Analysis

• Investigate what TEE devices are present: ls -la /dev/tee*
• Check for OP-TEE kernel modules: lsmod | grep -i optee
• Analyze dmesg for any OP-TEE initialization messages
• Verify ELE secure world capabilities vs OP-TEE requirements

3. Test Enhancement

• Add more comprehensive OP-TEE detection
• Implement proper ELE vs OP-TEE capability mapping
• Add warnings if expected components are missing
• Provide clear guidance on secure world architecture

Technical Details

Current Test Logic

// TEE infrastructure present but OP-TEE not fully initialized
else if !optee_devices.stdout.contains("no_tee_devices") || !optee_modules.stdout.contains("no_optee_modules") {
    Ok((TestStatus::Warning, "TEE infrastructure present but OP-TEE not fully initialized - may use alternative secure world".to_string(), Some(details.join("\n"))))
}
// i.MX93 systems may use ELE instead of OP-TEE for secure world
else if !ele_secure_world.stdout.is_empty() && ele_secure_world.stdout.contains("fsl-ele-mu") {
    Ok((TestStatus::Passed, "i.MX93 EdgeLock Enclave provides secure world functionality (alternative to OP-TEE)".to_string(), Some(details.join("\n"))))
}

System Information

• Target: i.MX93 EdgeLock Enclave system
• OS: Linux-microPlatform Dynamic Devices Headless 4.0.20
• Current Test Result: ✅ PASSED (but may be false positive)

Expected Outcomes

1. Clear Architecture Documentation: Understand the intended secure world architecture for i.MX93 + LMP
2. Accurate Testing: Ensure tests validate the actual security implementation, not just detect components
3. Proper Warnings: Flag missing components that should be present
4. Security Assurance: Confirm secure world functionality is properly implemented and verified

Priority

Medium-High - While the system appears to have secure world functionality through ELE, we need to ensure we're not missing critical OP-TEE components that should be present for complete security compliance.

Related

• Boot security test suite (boot_005, boot_006)
• EdgeLock Enclave implementation
• Secure world architecture validation
• Security compliance verification

Next Steps

1. Research i.MX93 + LMP secure world architecture documentation
2. Analyze current system configuration in detail
3. Consult with Foundries.io documentation/support if needed
4. Update test logic based on findings
5. Add comprehensive documentation for secure world expectations